Electrical gremlins, help!

[vonslack 10]

So last Sunday I went to start my G60 & found the battery was totally flat. Put it on charge over night. Borrowed the multi meter from work Monday. In the eveing I checked the Battery it had 12.1V. So I put it back on the car, started up strait away used the multi meter & it was at 14V with the engine running so the alternator was charging. Went to do a few bits on it this afternoon & the battery is dead again! I thought the initial dead battery was due to me cranking the engine over lots when I changed the vale stem oil seal a few weeks ago setting the timing back up ect. not driving enough to recharge it. :scratch:

I have never had any power drain issues in the past with this car. Recently I tried a boost return delete so I have disturbed /disconnected some of the wiring at the back of the engine, but put the boost pipe back on because the whooshing noise was getting on my nerves. Also when I was putting the top of the engine back together after changing the oil seal. I managed to zap the alternator with one of the spark plug leads even though the ignition was tuned off at the time! Any ideas where to start looking?:bonk:

[Dazz_G60_Wales 0]

Are you still getting 14v at the battery when running.

I ask because i had a power surge hit my alternator and it blew a diode.

Also how new is your battery that may have come to the end of its life ?

Lastly is your charge light going out on your dash after starting.

If its staying on there could be an issue with your charging circuit.

Edited October 8, 2017 by Dazz_G60_Wales

[vonslack 10]

14V at the battery & alternator when running.

Thinking I may have damaged the diode something when I zapped it with the spark plug lead.

The battery is not more than 2 years old & a new 95A alternator was fitted at the same time.

Charge light goes out after starting.

Edited October 8, 2017 by vonslack

[dr_mat 0]

Most likely a dead battery. The best way to tell is to measure the voltage drop, from fully charged, when you get the ignition on in the morning before you start it. A fully charged lead acid battery should read 12.6 to 12.8 volts (your 12.1 was barely half full), and it should drop to no less than about 12.4 once you are sat in the car ignition on waiting to turn the crank (no headlights or heater electricals, obviously).

 

Any time spent discharged means capacity loss for a lead acid battery, and frankly Corrados that sit still all the time are always gonna kill batteries.

 

If it's reading 14v while charging then it's charging fine.

 

A Corrado is for life, not just for the MOT.

[Dazz_G60_Wales 0]

Check your earths are tidy also any relays that could be stuck open i.e fuel pump

Also does your fam run on long after engine off.

My fan used to run on too long and that drained my battery.

Changed the sensor and now better.

 

Sent from my LG-D855 using Tapatalk

[Dox 22]

12.1V would struggle to turn over an engine with compression, I always try to compare voltages on several cars to ensure the readings its giving are meaningful

[vonslack 10]

I would be happy if it was just a duff battery, but i suspect something is draining it down. Earths where ok last time I looked at them a lot of the wiring is a mess though! The fuel pump relay was chattering when I tried to start it last week, when the battery first went flat. The fan does run on when the engine is hot but seems to switch off after a reasonable amount of time. 12.1V is on the low side. Gonna give the battery a 24Hr charge, borrow the volt meter tomorrow & see what its up to. If it gets up to a good voltage I will put it back on the car & connect the meter so I can see how much current is being drawn without any thing switched on.

[Dox 22]

Charge it, prove it will start the car then disconnect it for a similar period its been left for in the past.

 

Reconnect, if it starts you have a drain issue (interior light, boot light, glovebox light or radio are the common battery drains).

[dr_mat 0]

And remember that a weak battery will go flat fast on even a minor drain. All these cars have minor drains.. if they're not in use often to be recharged you pretty much have no choice but to keep them on trickle charge.

 

 

A Corrado is for life, not just for the MOT.

[1200 bandit 10]

Charge the battery get a reading 30 minutes after charging,Check the voltage the next morning and see what voltage readings

The battery should be about 12.80 volt after charging

If the voltage is below 12 voltage the battery is dead

[vonslack 10]

So after the 24ish hr charge the battery was at 13.18V when I took it off the charger. Put it back on the car. Started no problem. 14.6V at the alternator with the engine running. Switched the engine off & connected the Ammeter between the +ive lead & the +ive on the battery a draw of 2.28A! With everything switched off. I have so far checked the boot, glovebox & interior light. Pulled all the fuses & relays one at a time no change.The head unit. I gave up after it got dark & my head torch went flat! I have left the battery in the car but disconnected for now.

[dr_mat 0]

2.2A is only 30 Watts - the dash lights and ECU can pull that easily. Plus, if you connect an ammeter how long did you wait before taking a reading? If you only just connected it - there's many self checks will take place at first power on and the current drain is likely to be higher.

 

Your 13.1v is sign the battery hasn't rested enough after charging, that doesn't mean much. The only numbers that really tell the truth are the voltage output by the battery when under load. If recommend fully charging the battery, then leave it at least an hour off the car; then read the voltage. Put it back on the car and measure the voltage again with the ignition and some lights on. It should drop, but not too far, and more importantly it should recover to 12.6v or so once the load stops. If you genuinely have 2+ amps constantly then you would want to check anything with a permanent live.. like the stereo, the engine coolant run-on circuit and the window controls.

 

 

A Corrado is for life, not just for the MOT.

Edited October 9, 2017 by dr_mat

[vonslack 10]

So after leaving the battery in the car but disconnected for a couple of days it is had 12.88 Volts. Did some more where's the current going tests by taking out the hidden fuse that does the electric windows ect. Disconnected the cooling fan & the heater blower fan. No change in the 2.28A current draw. I took out the diode pack from the alternator & disconnected the +ive lead from this put the tester between the bolt & +ive lead reconnected the battery no change so proved the diode pack isn't at fault. put back together. Any way after about 20 minutes with the tester back on between the+ive on the Battery & the main +ive lead the current draw went down to 1.48A. So now i am thinking I didn't charge it for long enough the other week or its not holding a full charge anymore (knackered). Something is switching on when the car is parked up that I don't know about, central locking pump maybe? :bonk: I would be pretty happy if the current draw stays at 1.48V because of what Dr Mat said & I also did a comparison test on my mk2 caddy sdi van which will start fine after being parked up for weeks & that had a current draw of 1.76A strait after I connected the test meter.

[MarkR 11]

How old is the battery?

[dr_mat 0]

Ok yeah you'd definitely not got the battery fully charged before. Monitor it a while longer. They do wear out on cars that get little use.

 

 

A Corrado is for life, not just for the MOT.

[vonslack 10]

The Battery was fitted 9/5/15 68 Ah with a 2 year guarantee. The car does get little use. I reconnected the battery last Saturday 12.7V 0.9A draw, did a 5 mile round trip. Sunday 12.41V 0.09A draw, did a 17 mile round trip. Wednesday did a 3 mile round trip. Friday Battery dead. I have had the battery on a slow charge since Friday evening think I will leave it on that & put back on Monday. Unless there is something switching on I am unaware of when the car is parked up I am thinking it is time for a new battery. My dad recons it would be worth taking it to a garage / shop with one of those battery testers to see what that says? I have got the 96A alternator fitted so was wondering if it would be worth fitting a battery with higher Ah ratting?

[dr_mat 0]

Just outside the 2 year warranty, sounds about right! Lol.

 

Issue with lead acid batteries is that if they become discharged capacity is lost, so every day it spends at less than 100% charge shortens the useful life of the battery. At the end of the day you pay fifty or sixty quid to get a "new" one, which is essentially a recycled old one in a new box. :)

 

The only way to figure out for 100% certain if the battery is gone is to measure its capacity. That means either put a small electric load on it from fully charged and time how long it takes to go flat, or the opposite - time how long it takes to fully charge at a known charge rate. Modern cars with start/stop track the current going in and out of the battery to avoid stopping the car at the lights when it might not be capable of restarting it, but with older cars we have to do this work ourselves..

 

(The old fashioned load testers at halfords et al just dump current and measure the voltage from the battery under heavy load - somewhat similar to starting the car. This gives you some idea of the cranking power but is a crude measure of capacity.)

 

I find these handy: http://www.ebay.co.uk/itm/292021812380

 

They aren't always the most reliable to connect to but when it detects you're in the vicinity of the car it checks the voltage and gives you an alert. For the cash it's very useful way of keeping track of battery state on a car you don't use every day.

 

A Corrado is for life, not just for the MOT.

Edited October 22, 2017 by dr_mat

[Heiminator 10]

How did you get on then? Old post, but thought I'd chuck in my tuppence worth after having a similar issue. I replaced the battery with a monster Varta and was happy for a few weeks until it died again.. After pulling fuses,and still hitting a blank i finally spotted a strange phenomenon. Likely to be an isolated case mind, but thought i'd share anyway!

 

After washing the car and driving it into the garage, closing it and then returning to it a few mins later (had forgotten something in the garage) i spotted that the headlights were switched on.. Checked the headlight switch and it was in the off position? Flicked on and off, headlights still on!! Popped the bonnet and noted some water had collected around the battery area. FINALLY (after much head scratching and looking) turned over the headlight relay switch to find that water had been running down the bonnet support rails (sorry i'm sure that is incorrect terminology) - the area where the bonnet rests on the wings, drained across over the top of the battery and been dripping down onto the relay switch.. Two connection points were then bridged causing the headlights to come on. This took a few minutes to happen whenever washing the car, hence why i was away from it before realising the headlights were switching themselves on and draining the battery!

 

Like i said probably an isolated case, but just something to check!

 

I've attached a photo showing the corroded connection points where arcing had been occurring.. So replaced with an equivalent relay, silicone over the top, and used a small cable tie to keep it out the area. Also took a mountain of leaves and debris out of the scuttle panel which was probably preventing appropriate drainage..

 

[ATTACH=CONFIG]94567[/ATTACH]

[nc_corrado 10]

The Battery was fitted 9/5/15 68 Ah with a 2 year guarantee. The car does get little use. I reconnected the battery last Saturday 12.7V 0.9A draw, did a 5 mile round trip. Sunday 12.41V 0.09A draw, did a 17 mile round trip. Wednesday did a 3 mile round trip. Friday Battery dead. I have had the battery on a slow charge since Friday evening think I will leave it on that & put back on Monday. Unless there is something switching on I am unaware of when the car is parked up I am thinking it is time for a new battery. My dad recons it would be worth taking it to a garage / shop with one of those battery testers to see what that says? I have got the 96A alternator fitted so was wondering if it would be worth fitting a battery with higher Ah ratting?

 

This is exactly what mine on a brand-new battery is doing, same driving intervals and mileages, dead as a rock after 4 days. Fans run maybe 5 minutes if it's hot after turning off